The requirement to provide security in computer systems has led to the development of a variety of approaches for uniquely identifying microprocessors and other semiconductor devices that are part of the computer systems. Such approaches have included methods of inserting unique identification codes into integrated circuits of the semiconductor devices used in the computer systems. The challenge in mass producing semiconductor devices, wherein each die has a unique identification, includes maintaining quick manufacturing time, unclonability, and low costs.
Examples of some existing methods of incorporating unique identifications into semiconductor devices are as follows. A unique identification number may be stored in a non-volatile memory of the semiconductor device or fuses on the device may be blown to create the unique identification. However, these methods require additional circuitry on the semiconductor device resulting in increased size and cost of the individual die. Further, these methods typically yield semiconductor devices which are susceptible to being replicated or cloned.